The tremors kept the Garachicans in suspense all night until an hour before dawn on May 5, 1706, an outbreak abruptly resounded in the distance, as recorded by Fray Domingo José Cassares in his chronicles. Then there were other outbursts. At an altitude of 1,300 meters, on the steep slopes of the Garachico hills, and 6.5 kilometers from the coastal town, a 950-meter fracture with more than 12 eruptive foci was opened. That is where the lava started to come out, not far from Teide. The eruption of what would be called the Trevejo volcano –also known as Arenas Negras or Montaña Negra– was the one that caused the greatest social and economic impact of the 17 on which data are available in the history of the Canary Islands. The lava flows and balls, along with the thousands of fires that they caused in their dizzying descent, took away crops, homes, public spaces and an important part of what had been the main port of Tenerife. There were no fatalities but considerable material damage.
An hour before dawn on May 5, 1706, an explosion resounded in the heights of the town: a 950-meter fracture began to spew lava.
“On May 5, 1706, that fierce torrent of rocks and matter burning in two arms burst over the top of the high cliff and running wildly over the town, upsetting and reducing everything to ashes,” wrote 70 years later the historian José de Viera y Clavijo, who added: «An arm blocked the port, withdrawing the sea and leaving only an uncomfortable caletón, even for small vessels. Another burned the parish church, the convent of San Francisco, the monastery of Santa Clara and the entire Calle de Arriba, where the most sumptuous buildings were, of which noble fragments are preserved. Those inhabitants hardly had time and courage to flee the new land. Women, old men, children, nuns, the sick … some on horseback, others on foot, others by hand, others dragged out in droves towards Icod, loaded with the most precious jewels ». Regarding the damages, Viera y Clavijo said that “the loss was imponderable and the change in the terrain, appalling.” “The vineyards, the waters, the birds, the port, the commerce and the neighborhood disappeared”, concludes the priest and writer.
The Garachico eruption lasted 40 days – until June 13 – and occurred in the period with the highest concentration of volcanic events in the history of the Archipelago. In just a year and a half, between the last day of 1704 and June 1706, thousands of earthquakes and four eruptions were registered in Tenerife: Siete Fuentes (Arico, from December 31, 1704 to January 4, 1705), Volcán de Fasnia (from January 5 to 16, 1705), Volcán de Arafo (from February 2 to March 27, 1705) and the town of Garachico. This last eruption was primed with the one that immediately after the Conquest of Tenerife by the Castilians and until 1633 was the main port of the Island, through which all commercial activity passed. Cane sugar exports first and wine later through the small pier made Garachico the second most important town after the then capital, La Laguna.
The decline, however, had begun before the eruption, when the Garachiquense port lost its supremacy over those of Santa Cruz and La Orotava –since 1812 Puerto de la Cruz–. But the thrust came with the lava from the volcano. According to the work Impacto de las coladas of 1706 in the city of Garachico, by researchers from the University of La Laguna Carmen Romero and Esther Beltrán, the eruption constitutes “an excellent example of how a low-risk event can turn into a disaster.” . One piece of information is revealing: Garachico went from having 1,600 inhabitants in 1706 to 400 a year later. 75% of the inhabitants abandoned their houses and lands when they were devastated by lava flows and fires or by fear that a volcanic episode would be repeated. No one died but the Garachicans knew that 16 people had lost their lives in other parts of Tenerife due to the continuous earthquakes of the previous months.